Antigen testing generally refers to neocoronavirus antigen testing. A negative antigen test is not necessarily negative, and its accuracy is still low compared to nucleic acid testing. First of all, the antigen test consists of 4 steps: sampling, extracting the sample, spiking the sample, and reading the result. There are some false negatives, for example, in the process of nasopharyngeal specimen collection, the nasal cavity is not deep enough and not rotated sufficiently to remove the secretions in the nasal cavity, the results will be greatly affected in the subsequent elution and reading process. In addition, the sensitivity and specificity of the different antigen tests are not 100%. Currently, WHO recommends that the sensitivity of antigen tests should not be less than 80% and the specificity should not be less than 97%, so there is a possibility of false-negative results in the antigen test kits themselves. Therefore, the results of antigen detection are affected by both the reagent itself and personal operation, and a single negative result in an epidemic area does not necessarily mean that it is negative, but also needs to be combined with nucleic acid testing for auxiliary verification.